package crmdna.practice;

import static crmdna.common.OfyService.ofy;

import java.util.ArrayList;
import java.util.List;

import com.google.appengine.api.memcache.MemcacheServiceFactory;
import com.googlecode.objectify.Key;

import crmdna.client.Client;
import crmdna.common.APIException;
import crmdna.common.APIResponse.Status;
import crmdna.sequence.Sequence;
import crmdna.sequence.Sequence.SequenceType;
import crmdna.user.User;
import crmdna.user.User.Action;
import crmdna.user.User.ResourceType;

public class Practice {
	public static class PracticeProp implements Comparable<PracticeProp> {
		public long practiceId;
		public String name;
		public String displayName;

		@Override
		public int compareTo(PracticeProp arg0) {
			return name.compareTo(arg0.name);
		}
	}

	public static PracticeProp create(String client, String displayName,
			String login) {

		Client.ensureValidClient(client);
		User.ensureAccess(client, login, ResourceType.PRACTICE, 0, Action.WRITE);

		String name = displayName.toLowerCase();

		List<Key<PracticeEntity>> keys = ofy(client).load()
				.type(PracticeEntity.class).filter("name", name).keys().list();

		if (keys.size() != 0)
			throw new APIException(Status.ERROR_RESOURCE_ALREADY_EXISTS,
					"There is already a practice with name [" + displayName
							+ "]");

		String key = getUniqueKey(client, name);
		long val = MemcacheServiceFactory.getMemcacheService().increment(key,
				1, (long) 0);

		if (val != 1)
			throw new APIException(Status.ERROR_RESOURCE_ALREADY_EXISTS,
					"There is already a group with name [" + displayName + "]");

		PracticeEntity entity = new PracticeEntity();
		entity.practiceId = Sequence.getNext(client, SequenceType.PRACTICE);
		entity.name = name;
		entity.displayName = displayName;
		ofy(client).save().entity(entity).now();

		return entity.toProp();
	}

	private static String getUniqueKey(String namespace, String name) {
		return namespace + "_" + SequenceType.PRACTICE + "_" + name;
	}

	public static PracticeEntity safeGet(String client, long practiceId) {

		Client.ensureValidClient(client);

		PracticeEntity entity = ofy(client).load().type(PracticeEntity.class)
				.id(practiceId).get();
		if (null == entity)
			throw new APIException(Status.ERROR_RESOURCE_DOES_NOT_EXIST,
					"Practice [" + practiceId + "] does not exist");

		return entity;
	}

	public static PracticeProp rename(String client, long practiceId,
			String newDisplayName, String login) {
		Client.ensureValidClient(client);
		User.ensureAccess(client, login, ResourceType.PRACTICE, 0, Action.WRITE);

		PracticeEntity entity = safeGet(client, practiceId);

		String newName = newDisplayName.toLowerCase();

		if (entity.name.equals(newName)) {
			// ideally should be inside a transaction
			entity.displayName = newDisplayName;
			ofy(client).save().entity(entity).now();
			return entity.toProp();
		}

		List<Key<PracticeEntity>> keys = ofy(client).load()
				.type(PracticeEntity.class).filter("name", newName).keys()
				.list();
		if (keys.size() != 0)
			throw new APIException(Status.ERROR_RESOURCE_ALREADY_EXISTS,
					"There is already a practice with name [" + newDisplayName
							+ "]");

		String key = getUniqueKey(client, newName);
		long val = MemcacheServiceFactory.getMemcacheService().increment(key,
				1, (long) 0);

		if (val != 1)
			throw new APIException(Status.ERROR_RESOURCE_ALREADY_EXISTS,
					"There is already a practice with name [" + newDisplayName
							+ "]");

		// ideally should be inside a transaction
		entity.name = newName;
		entity.displayName = newDisplayName;
		ofy(client).save().entity(entity).now();

		return entity.toProp();
	}

	public static List<PracticeProp> getAll(String client) {
		Client.ensureValidClient(client);

		List<PracticeEntity> entities = ofy(client).load()
				.type(PracticeEntity.class).order("name").list();

		List<PracticeProp> props = new ArrayList<>();
		for (PracticeEntity entity : entities)
			props.add(entity.toProp());

		return props;
	}

	public static void delete(String client, long practiceId, String login) {

		Client.ensureValidClient(client);
		User.ensureAccess(client, login, ResourceType.PRACTICE, 0, Action.WRITE);

		// there should not be any program type referencing this
		throw new APIException(Status.ERROR_NOT_IMPLEMENTED,
				"This functionality is not implemented yet");
	}
}
